000
AXPZ20 KNHC 202151
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC MON FEB 20 2012

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS 
BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND 
METEOROLOGICAL ANALYSIS.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2030 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

THE MONSOON TROUGH AXIS WAS ANALYZED FROM 02N101W TO 05N112W TO 
04N121W TO 05N126W TO 00N133W. SCATTERED MODERATE CONVECTION WAS 
WITHIN 210 NM S OF THE AXIS BETWEEN 104W AND 110W.

...DISCUSSION...

THE NORTHERN STREAM PATTERN WILL SLOWLY SHIFT E OVER THE NEXT 
FEW DAYS. AN UPPER ANTICYCLONE N OF THE AREA NEAR 37N140W WILL 
STRENGTHEN AS IT DRIFTS ABOUT 5 DEGREES FARTHER E...CHASING THE 
MEAN TROUGH CENTERED FROM 32N120W TO 28N125W TO 28N140W 
SOUTHEASTWARD THROUGH NE WATERS AND NW MEXICO. A NEW BATCH OF 
NORTHERN STREAM ENERGY IS CURRENTLY DROPPING INTO THE BACKSIDE 
OF THIS MEAN TROUGH AND WILL SLOWLY SWEEP THROUGH BAJA 
CALIFORNIA NORTE TUE. AT THE SURFACE...THE SUBTROPICAL RIDGE 
EXTENDS FROM THE 1035 MB SUBTROPICAL HIGH CENTERED NEAR 33N143W 
SOUTHEASTWARD TO 15N105W. THE HIGH IS EXPECTED TO 
STRENGTHEN AND DRIFT E LIKE ITS PARENT ANTICYCLONE ALOFT. 
SURFACE TROUGHING ASSOCIATED WITH THE MEAN UPPER TROUGH PASSING 
THROUGH BAJA CALIFORNIA WILL INCREASE THE PRES GRADIENT AGAINST 
THE SUBTROPICAL RIDGE OVER THE GULF OF CALIFORNIA. FRESH NW TO N 
WINDS ARE EXPECTED IN THE NORTHERN GULF OF CALIFORNIA TUE 
AFTERNOON THROUGH WED AFTERNOON. 

FURTHER SOUTH...A BROAD AND NEGATIVELY TILTED UPPER TROUGH 
EXTENDS FROM 20N125W TO 05N120W. MID-LEVEL ENERGY NEAR THE 
SOUTHERN EDGE OF THIS TROUGH IS ENHANCING THE SURFACE TROUGHING 
ALONG THE MONSOON TROUGH W OF 115W. IN TURN...THIS IS INCREASING 
THE PRES GRADIENT BETWEEN THE MONSOON TROUGH AND THE SUBTROPICAL 
RIDGE W OF 115W...FORCING FRESH TO STRONG TRADE WINDS OVER MUCH 
OF THE AREA. THE MID-LEVEL ENERGY IS EXPECTED TO DRIFT WESTWARD 
OVER THE NEXT TWO DAYS...AND THE AREA OF TRADE WINDS IS FORECAST 
TO SHIFT W IN RESPONSE. MEANWHILE...NW SWELL WITH 12 TO 14 
SECOND PERIODS AND HEIGHTS OF 8 TO 12 FT CONTINUE TO PUSH INTO 
THE AREA AND MIX WITH FRESH NE SWELL ASSOCIATED WITH THIS 
PERSISTING TRADE WIND FLOW. 

...GAP WINDS...

GULF OF TEHUANTEPEC...THE 1620 UTC ASCAT PASS SHOWS WINDS HAVE 
DIMINISHED TO 20 KT IN THE GULF OF TEHUANTEPEC AND ARE FORECAST 
TO DROP BELOW 20 KT BY SUNSET.

GULF OF PAPAGAYO...THE PRES GRADIENT BETWEEN RIDGING IN THE NE 
GULF OF MEXICO AND TROUGHING TO THE S OF THE GULF OF PAPAGAYO IS 
FORCING FRESH NE WINDS HERE. WINDS WILL INCREASE TO STRONG IN 
THE EARLY MORNING HOURS WITH THE AID OF LOCAL DRAINAGE FLOW. THE 
TRADE WIND FLOW OVER THE SW CARIBBEAN WILL INCREASE MON... 
ALLOWING THE AREA OF FRESH TO STRONG WINDS TO EXPAND WESTWARD 
DOWNWIND OF THE GULF OF PAPAGAYO.

GULF OF PANAMA...SHIP A8SE8 REPORTED 22 KT NORTHERLY WINDS NEAR 
06N80W AT 1800 UTC. STRENGTHENING FLOW FROM THE CARIBBEAN WILL 
PUSH ACROSS THE ISTHMUS OF PANAMA AND INTO THE GULF OF PANAMA 
THROUGH WED. 

$$
SCHAUER